1. Field of the Invention
This invention concerns a device to feed reinforcement rods. To be more exact, this invention concerns a device suitable to cooperate with an excavation equipment in providing that excavation equipment with non-recoverable reinforcement rods employed in the lengthwise reinforcing of tunnels.
2. Discussion of Prior Art
The device of the invention and the excavation equipment are normally borne on an excavation machine working at the excavation site.
The state of the art covers various methods and devices employed in the reinforcement of tunnels.
One of the systems used most often consists in making a series of lengthwise holes about the vault of the tunnel.
At the end of each drilling step, which is carried out with suitable tools on a shaft, the shaft is withdrawn from the hole drilled in the wall and a cement agglomerate is injected into the hole.
Thereafter a non-recoverable reinforcement rod having a length substantially the same as that of the hole thus made is inserted into the cement agglomerate to complete the reinforcement.
The cycle is repeated at each hole drilled and therefore there is a continuous handling of the drilling shaft alternated from time to time with the feed of new rods to be inserted into the holes made in the wall.
The drilling and the insertion of the reinforcement rods are normally carried out by the same excavation equipment, which is borne on an operating machine.
The operating machine brings the excavation equipment, provided with the drilling shaft, from time to time to the hole to be drilled.
As each hole is completed, the excavation equipment is normally moved to one of its two lower positions at the sides of the excavation machine, where the drilling shaft is removed and the reinforcement rod to be inserted is fitted by hand.
The drilling equipment is then brought back to the hole previously made and filled with cement agglomerate in the meantime.
During these working steps the engagement of the reinforcement rods, which are usually deposited on the ground near the excavation machine, and the lifting of the rods for their positioning on the excavation equipment are especially burdensome. These operations are even more burdensome when it is realized that these rods may even be 20-22 meters long or more.